What is this black plastic housing (circled in red as best I could) that is connected with a TEE fitting to the intake, just behind the air filter?

I see the filter life sensor is attached to it, but the plastic housing itself seems to not be connected to anything else.

Is it analogous to the plastic resonator that is on top of the pickup truck Duramax (last photo)?

Resonator.

Thanks. The list of oem parts I don't need is growing.